The CHAMP mission provided a great amount of geomagnetic data all over the globe from 2000 to 2010. Its dense data coverage has allowed us to build GRIMM - GFZ Reference Internal Magnetic Model - which has the highest ever resolution for the core field in both space and time. We have already modeled the fluid flow in the Earth's outer core by applying the diffusionless magnetic induction equation to the latest version of GRIMM, to find that the flow evolves on subdecadal timescales, with a remarkable correlation to the observed fluctuation of Earth rotation. These flow models corroborated the presence of six-year torsional oscillations in the outer core fluid. Torsional oscillation (TO) is a type of hydromagnetic wave, theoretically considered to form the most important element of decadal or subdecadal core dynamics. It consists of relative azimuthal rotations of rigid fluid annuli coaxial with the mantle's rotation and dynamically coupled with the mantle and inner core. In preceding works, the TOs have been studied by numerical simulations, either with full numerical dynamos, or solving eigenvalue problems ideally representing the TO system. While these studies drew insights about dynamical aspects of the modeled TOs, they did not directly take into account the observations of geomagnetic field and Earth rotation. Particularly, there have been no observation-based studies for the TO using satellite magnetic data or models. In the proposed project, we aim at revealing the subdecadal dynamics and energetics of the Earth's core-mantle system on the basis of satellite magnetic observations. To that end, we will carry out four work packages (1) to (4), for all of which we use GRIMM. (1) We perform timeseries analyses of core field and flow models, to carefully extract the signals from TOs at different latitudes. (2) We refine the conventional flow modeling scheme by parameterizing the magnetic diffusion at the core surface. Here, the diffusion term is reinstated in the magnetic induction equation, which is dynamically constrained by relating it to the Lorentz term in the Navier-stokes equation. (3) We develop a method to compute the electromagnetic core-mantle coupling torque on the core fluid annuli, whereby the energy dissipation due to the Joule heating is evaluated for each annulus. This analysis would provide insights on whether the Earth's TOs are free or forced oscillations. (4) Bringing together physical implications and computational tools obtained by (1) to (3), we finally construct a dynamical model for the Earth's TOs and core-mantle coupling such that they are consistent with GRIMM and Earth rotation observation. This modeling is unique in that the force balances concerning the TOs are investigated in time domain, as well as that the modeling also aims at improving the observation-based core flow model by considering the core dynamics.
The sorption of anions in geotechnical multibarrier systems of planned high level waste repositories (HLWR) and of non-ionic and organic pollutants in conventional waste disposals are in the center of recent research. In aquatic systems, persistent radionuclides such as 79Se, 99Tc, 129I exist in a form of anions. There is strongly increasing need to find materials with high sorption capacities for such pollutants. Specific requirements on barrier materials are long-term stability of adsorbent under various conditions such as T > 100 C, varying hydrostatic pressure, and the presence of competing ions. Organo-clays are capable to sorb high amounts of cations, anions and non-polar molecules simultaneously having selectivity for certain ions. This project is proposed to improve the understanding of sorption and desorption processes in organo-clays. Additionally, the modification of material properties under varying chemical and thermal conditions will be determined by performing diffusion and advection experiments. Changes by sorption and diffusion will be analyzed by determining surface charge and contact angles. Molecular simulations on models of organo-clays will be conducted in an accord with experiments with aim to understand and analyze experimental results. The computational part of the project will profit from the collaboration of German partner with the group in Vienna, which has a long standing experience in a modeling of clay minerals.
Prehistoric pits are filled with ancient topsoil material, which has been preserved there over millennia. A characteristic of these pit fillings is that their colour is different depending on the time the soil material was relocated. Soil colour is the result of soil forming processes and soil properties, and it could therefore indicate the soil characteristics present during that specific period. To the best of our knowledge, no investigation analysed and explained the reasons for these soil colour changes over time. The proposed project will investigate soil parameters from pit fillings of different archaeological periods in the loess area of the Lower Rhine Basin (NW-Germany). It aims to implement the measurement of colour spectra as a novel analytical tool for the rapid analyses of a high number of soil samples: the main goal is to relate highresolution colour data measured by a spectrophotometer to soil parameters that were analysed by conventional pedogenic methods and by mid infrared spectroscopy (MIRS), with a main focus on charred organic matter (BPCAs). This tool would enable us to quantify the variation of soil properties over a timescale of several millennia, during different prehistoric periods at regional scale and for loess soils in general. Detailed information concerning changing soil properties on a regional scale is necessary to determine past soil quality and it helps to increase our understanding of prehistoric soil cultivation practices. Furthermore, these information could also help to increase our understanding about agricultural systems in different archaeological periods.
Research question: Agri-environment schemes play an increasingly important role in European CAP (Common Agricultural Policy) to support biodiversity and environment in agricultural landscapes. They have been implemented since 1992 and now cost a yearly 1.7 billion Euro. Still, there is no conclusive evidence that these schemes actually do contribute to the conservation of particularly biodiversity. The primary objective of this project is to evaluate the (cost-) effectiveness of European agri-environment schemes in protecting biodiversity and to determine the primary processes that determine their effectiveness. This project furthermore aims to determine how CAP may be introduced in candidate EU-members without unacceptable loss of biodiversity. It will provide simple guidelines how researchers, governmental authorities may efficiently evaluate agri-environmental measures. Aim: Agri-environment schemes have been used to protect biodiversity and environment in agricultural areas since 1992. Their effectiveness has never been reliably evaluated. This project aims to evaluate the (cost-)effectiveness of agri-environment schemes with respect to biodiversity conservation in five European countries. It will determine the proper scales that have to be addressed for conservation efforts for a range of species groups. It will determine the most important environmental factors that influence the effectiveness of the schemes. Based on this, recommendations will be made how the effectiveness of schemes may be improved and simple guidelines will be produced how ecological effects of agri-environment schemes can be evaluated efficiently by governmental authorities or other institutions. The ecological effects of the introduction of CAP in a candidate EU-member will be investigated to reduce negative side effects of anticipated land-use changes Scientific methods: We will examine the effectiveness of agri-environment schemes by surveying pairs of fields: a field with an agri-environment scheme and a nearby field that is conventionally managed. In five countries, in each country in three areas, and in each area on seven pairs of fields the species richness of birds, plants and three insect groups (pollinators, herbivores, predators) will be determined. Effects of schemes on pollination efficiency and pest control will be examined using indicator communities. Correlative studies will examine the effects of landscape structure, land-use intensity and species pool on the effectiveness of agri-environmental measures. The spatial scale that is relevant to nature conservation efforts will be investigated via the spatial distribution of species groups. The results will be used to formulate recommendations how to improve the effectiveness of agri-environment schemes and to construct a set of simple guidelines how schemes can be evaluated efficiently yet reliably.
We study the effects of plants and root-associated fungi on wind erosion within the alpine environment of Tibet. China is one of the countries most affected by desertification processes and Tibet, in particular, a key region in desertification combat. The presented project focuses on the Barkha Plain surrounded by Mount Kailash and the Lake of Manasarovar (Ngari Prefecture). This Western Tibet region experienced little scientific attention but, nowadays, faces rapidly increasing touristic activities and expanding local settlements associated with socio-economic changes that are serious threats to the delicate ecological balance and potential triggers of desertification. It exists almost unanimous agreement that revegetation is the most efficient and promising strategy to combat wind erosion and desertification in the long term. However, re-colonising success is often poor, mainly under extreme environmental conditions. Compared to conventional practices, the approach of the presented project attains better accordance with natural succession processes and promises acceleration of both plant and soil development and, conclusively, more efficient desertification control. The project assesses the potential of native plants and symbiotic fungi to control wind erosion and desertification processes. It aims to identify key plants and fungi that increase soil aggregate stability and efficiently drive succession into a natural and self-maintaining cycle of the ecosystem. Furthermore, it provides crucial information for implementing environmentally compatible and cost-effective measures to protect high-elevation ecosystems against desertification. Within three successional stages (early, intermediate, late), field investigations are performed on the basis of Modified-Whittaker plots. Classic methods of vegetation analysis and myco-sociology are combined with analysis of distribution patterns at different scales (patchiness, connectivity). Comprehensive soil analysis is performed comprising grain size distribution, aggregate stability, pH as well as water and nutrient contents. Additionally, important parameters of wind erosion are measured concurrently and continuously to assess their magnitude and variability with respect to vegetation and soil at different levels of development. The parameters addressed, include sediment transport, air temperature, radiation, precipitation, relative humidity as well as speed and direction of wind. Surface moisture is recorded periodically and roughness described. Species and environmental parameters are checked for spatial correlation. Cutting edge technologies are applied in laboratory work, comprising molecular methods for fungal species identification and micro-tomography to analyse soil structure. Furthermore, successfully cultivated fungi and plants are subject of synthesis experiments and industrial propagation in view of practical implementation in restoration measures.
Zur Bestimmung der Konzentrationen linearer Alkylbenzolsulfonate (LAS) und Alkylethersulfate (AES) in Kläranlagenabläufen wurden 7-Tagesmischproben (n=33) an Abläufe von 33 konventionellen Kläranlagen in Deutschland genommen. Zudem wurden an vier der untersuchten Kläranlagen die Zuläufe beprobt und ebenfalls auf LAS und AES untersucht, um Rückschlüsse auf die Entfernung dieser Tenside in konventionellen Kläranlagen ziehen zu können. Insgesamt umfasste die Studie die Analyse von vier LAS-Homologen (C10-C13) sowie von jeweils 10 Ethoxymeren zweier Homologe von AES (C12 und C14, jeweils mit 0-9 Ethoxygruppen). Die Probenvorbereitung bestand aus der Entfernung der wässrigen Phase mit Hilfe eines Rotations-Vakuum-Konzentrators und anschließender Resolvatisierung des Trockenrückstandes in einer definierten Menge Reinstwasser und Acetonitril. Die Identifikation und Quantifizierung der Zielanalyten erfolgte mittels Hochleistungsflüssigkeitschromatographie mit Tandem-Massenspektrometrie-Kopplung (HPLC-MS/MS). Die Leistungsfähigkeit der analytischen Methoden wurde in Leitungswasser und Kläranlagenablauf evaluiert. Die Analysemethoden zeigten für beide Matrices eine allgemein gute Richtigkeit sowie Präzision. Basierend auf den geschätzten mittleren Konzentrationen einzelner LAS-Homologe wurde eine mittlere Gesamtkonzentration von 14,4 Mikro g/L in Kläranlagenabläufen ermittelt. Verglichen mit LAS, wurden für AES stets geringere Gesamtkonzentrationen im Ablauf gemessen: Die mittlere AES-Gesamtkonzentration in den Abläufen betrug 0,57 Mikro g/L. Zwischen den Gesamtkonzentrationen von AES und LAS bestand keine Korrelation. In den Zuläufen beprobter Kläranlagen wurden im Mittel 3.200 Mikro g/L LAS detektiert. Damit betrug die mittlere Entfernung für LAS 99,6 %. Die mittlere AES-Konzentration im Kläranlagenzulauf belief sich auf 680 Mikro g/L, was einer mittleren AES-Entfernung von größer als 99.9% entspricht. Retrospektives Screening von 1.564 Tensiden und deren Transformationsprodukte (TPs) erfolgte durch ein zweites Labor unter Anwendung der Ultrahochleistungsflüssigkeitschromatographie mit Flugzeitmassenspektrometer-Kopplung (UHPLC-QTOF-MS). In vielen Fällen wurde die Konzentration von LAS von der Summe der Konzentrationen der Neben- und Transformationsprodukte von LAS überstiegen. Für die LAS-Nebenprodukte Dialkyltetralinsulfonate (DATS) lag die maximale Summenkonzentration bei 19 Mikro g/L, für die Sulfophenylalkylcarbonsäuren (SPACs) bei 17 Mikro g/L und für die Sulfotetralinalkylcarbonsäuren (STACs) bei 5,3 Mikro g/L. Hohe Konzentrationen von bis zu 7,4 Ìg/L wurden für Polyethylenoglycole in den Abwasserproben bestimmt. Die Gesamtkonzentration aller quantifizierten Tenside, TPs und Nebenprodukte in einer einzelnen Probe betrug bis zu 82 Mikro g/L.
The baking industry includes companies that make value added products including bread, buns, rolls, doughs, desserts, crusts, pastas, cookies, biscuits, crackers etc. that are either baked or frozen. The use of refrigeration technology has made a bakery's location independent of its customers, thereby broadening the geographic market potential and contributing to the growth of this sector. However, this development does have a cost. Bakeries are energy intensive, using large amounts of electricity and natural gas to operate the refrigeration system, compressed air system and ovens. These energy costs are rising and becoming a significant portion of the ingredient costs of baked goods. About 10Prozent of the total electrical and thermal energy consumption of all craft enterprises originates from the bakery sector. Accordingly there are many possibilities for energy reduction and therefore to permanently reduce the costs for the enterprises and thus to make a sustainable contribution to climate protection. Making changes in the energy use patterns of bakeries would be the fastest way to affect the energy profile of bread, because bakery is responsible for 70 and 80Prozent of the total energy consumption in conventional and organic bread production, respectively. Overall aim of the NanoBAK-Collaborative Project is the efficient energy management in the baking industry. Specific aim of this project is the development and demonstration of a novel marketable climatic chamber with an innovative, energy-saving nano-aerosol humidification system. Lab tests have shown that the energy consumption using ultrasonic humidification is significantly lower than for conventional humidification. The innovative ultrasonic humidification of the NanoBAK Project saves up to 50Prozent of energy compared to conventional humidifiers. Furthermore the quality of the bakery goods is of high value, so that the ultrasonic humidifier is profitable both energetically and qualitative.
The ATAAC project aims at improvements to Computational Fluid Dynamics (CFD) methods for aerodynamic flows used in today's aeronautical industry. The accuracy of these is limited by insufficient capabilities of the turbulence modelling / simulation approaches available, especially at the high Reynolds numbers typical of real-life flows. As LES will not be affordable for such flows in the next 4 decades, ATAAC focuses on approaches below the LES level, namely Differential Reynolds Stress Models (DRSM), advanced Unsteady RANS models (URANS), including Scale-Adaptive Simulation (SAS), Wall-Modelled LES, and different hybrid RANS-LES coupling schemes, including the latest versions of DES and Embedded LES. The resources of the project will be concentrated exclusively on flows for which the current models fail to provide sufficient accuracy, e.g. in stalled flows, high lift applications, swirling flows (delta wings, trailing vortices), buffet etc. The assessment and improvement process will follow thoroughly conceived roadmaps linking practical goals with corresponding industrial application challenges and with modelling/simulation issues through stepping stones represented by appropriate generic test cases. The final goals of ATAAC are: - to recommend one or at most two best DRSM for conventional RANS and URANS- to provide a small set of hybrid RANS-LES and SAS methods that can be used as reference turbulence-resolving approaches in future CFD design tools - to formulate clear indications of areas of applicability and uncertainty of the proposed approaches for aerodynamic applications in industrial CFD - Contributing to reliable industrial CFD tools, ATAAC will have a direct impact on the predictive capabilities in design and optimisation, and directly contribute to the development of Greener Aircraft.
The development of new technologies for the synthesis of innovative one dimensional (1D) materials is a key issue for fabricating advanced nanodevices with unique surface-related effects and quantum phenomena. The nitride nanomaterials, particularly group III nitrides, have attracted great interest due to their blue light and UV emission properties, piezoelectricity, high stability etc. In contrast to oxides, the synthesis of stoichiometric nitrides is a considerably more complicated task due to the lower reactivity of nitrogen. Therefore, the development of new nitridation technologies operating at low synthesis temperatures is a key challenge for modern materials science. The purpose of this project is to develop a hydrazine-based simple and efficient new technology for fabricating new 1D nanomaterials (nitrides, oxynitrides, oxides of Ge and Ge-In, Ge-Sn, Ge-Zn, Ge-Ga systems) and to furthermore investigate the properties of the emerging novel nanomaterials in order to evaluate their application potential in different nanodevices. Our new technological approach is based on the application of hydrazine for producing nitride and oxide nanomaterials. The advantage of hydrazine over ammonia as the conventionally used agent is its low pyrolysis temperature. Semiconductor surfaces then serve as catalysts for the low temperature decomposition of hydrazine via a chain reaction. Due to the low pyrolysis temperature and the formation of active radicals, a decrease of nitridation temperatures with hydrazine as a nitrogen source is expected. Oxynitride 1D nanomaterials will be synthesized following a similar route based on water-hydrazine mixtures. Preliminary syntheses of germanium nitride nanowires by annealing a Ge source in hydrazine vapor containing 3 molProzent of water molecules demonstrate the efficiency of our strategy as a simple, low-cost technology aiming for the mass production of functional nitride nanomaterials. Special emphasis will furthermore be placed on the application of the newly synthesized 1D nanomaterials in sensors for environmental control and on the fabrication of nano-sized photocatalysts for solar hydrogen production by water splitting. Germanium nitride was the first non-oxide photocatalyst which was used for water splitting. We suggest that the application of this material in the form of flat nanobelts can increase its catalytic efficiency, because a considerable fraction of the atoms are located at the surface of the nanobelts. The insights obtained from the project will lead to a deeper understanding of 1D nanomaterial growth mechanisms and they will facilitate the transition to the zero dimensional (0D) quantum-dot devices.
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